JP5099202B2 - Developing device, process unit, and image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a laser printer, a developing device mounted on the image forming apparatus, and a process unit.

  In an electrophotographic image forming apparatus, an electrostatic latent image is formed on the surface of a photosensitive drum, and toner is supplied to the electrostatic latent image on the photosensitive drum from a developing cartridge containing toner as a developer. As a result, a toner image is formed on the surface of the photosensitive drum. The toner image is transferred onto a sheet that is a transfer material, thereby forming an image on the sheet.

  For example, in Japanese Patent Application Laid-Open No. H10-260707, the developing cartridge is supported by a housing having an opening that opens toward the photosensitive drum, a housing chamber that is provided in the housing and accommodates toner, and is rotatably supported by the housing. And a developing roller arranged so that its outer peripheral surface is exposed from the opening, a plate spring member fixed to the housing, and a layer thickness regulating portion fixed to the lower end of the plate spring member, A layer thickness regulating member that regulates the thickness of the toner layer carried on the outer peripheral surface of the developing roller and a plate provided at both ends of the developing roller in the rotation axis direction to prevent the toner from leaking out of the housing And a seal member attached to the spring member.

  In such a developing cartridge, if there is a gap between the seal member and the layer thickness regulating portion, toner leaks through the gap to the outside of the housing. Therefore, when the seal member is stuck on the leaf spring, The sealing member was attached with double-sided tape with the utmost care so as not to generate a gap between the member and the layer thickness regulating portion.

JP 2005-189346 A

  However, the above developing cartridge has a problem in that it takes time to attach the seal member because high positioning accuracy is required when the seal member is attached to the leaf spring via the double-sided tape.

  Accordingly, the present application has been made in view of the above problems, and a developing device having a configuration in which a seal member can be easily assembled to a layer thickness regulating portion, and a process unit and an image forming apparatus including the developing device. It is intended to provide.

  In order to achieve this object, the invention according to claim 1 includes a developing roller carrying a developer on an outer peripheral surface, an opening that supports the developing roller rotatably and extends in a rotation axis direction of the developing roller. A casing having a portion, a thin plate member having one end fixed to the housing and extending in the direction of the rotation axis of the opening, and a free end portion of the thin plate member, A layer thickness regulating member that contacts the outer circumferential surface of the developing roller via the layer thickness regulating member that regulates the thickness of the developer layer on the outer circumferential surface of the developing roller, and the layer thickness in the rotation axis direction. A fixing member fixed on the thin plate member outside both ends of the restricting portion and forming a groove portion with the layer thickness restricting portion; and a length longer than the length of the groove portion in the rotation axis direction. And by fitting into the groove The have a suppressing seal member leakage of developer to the outside of the housing, comprising the.

  According to a second aspect of the present invention, in the first aspect of the present invention, a tip is formed on the bottom surface of the groove portion facing the lower surface of the seal member when the seal member is assembled to the groove portion. Is characterized in that a saw blade shape inclined inward in the rotational axis direction is formed.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the groove has a length of an opening facing the developing roller in the direction of the rotation axis. It is characterized by being formed shorter than the length of the bottom part.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the groove portion has a length of a bottom portion that is the thin plate member side in the rotation axis direction. It is characterized by being formed gradually shorter toward the downstream side in the rotation direction of the roller.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the seal member extends to the upstream side in the rotation direction of the developing roller from a portion where the seal member is assembled to the groove portion. It has the extended part extended in the rotating shaft direction of a developing roller, and engaging with the said layer thickness control part.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the seal member includes a base material having elasticity, and a raised material provided on the base material. The raised material is tilted in an oblique direction toward the inner side in the rotation axis direction as it goes downstream in the rotation direction of the developing roller.

  The invention according to claim 7 is the invention according to claim 6, wherein the outer end of the base material in the rotation axis direction is the outer end of the raised material in the rotation axis direction. It is characterized by projecting outward from the portion.

  According to an eighth aspect of the present invention, in the process unit, the developing device according to any one of the first to seventh aspects and a photosensitive device in which a developer image is formed by supplying the developer from the developing device. It is characterized by having a body.

  According to a ninth aspect of the present invention, there is provided an image forming apparatus comprising the process unit according to the eighth aspect, wherein the image forming apparatus is formed by an exposure unit that scans light with respect to the photoreceptor and the process unit. An image forming apparatus comprising: a transfer unit that transfers a developer image to a sheet; and a fixing unit that fixes a developer image formed on the sheet.

  According to the first aspect of the present invention, the seal member has a length longer than the length of the groove portion in the rotation axis direction, and is assembled in the groove portion between the fixing member and the layer thickness regulating portion. The seal member and the layer thickness restricting portion are in close contact with each other only by assembling to the groove portion. As a result, the seal member can be easily assembled to the layer thickness regulating portion.

  According to the invention described in claim 2, since the saw blade shape having the tip inclined inward in the rotational axis direction is formed on the bottom surface of the groove portion, when the seal member is assembled to the notch portion, the seal member The seal member is assembled in the groove portion so that moves inward in the rotation axis direction. Therefore, the seal member is more closely attached to the side wall portion of the groove portion in the rotation axis direction, so that toner leakage can be further suppressed.

  According to the invention described in claim 3, since the groove is formed such that the length of the opening facing the developing roller in the rotation axis direction is shorter than the length of the bottom on the thin plate member side, After the seal member is assembled in the groove, the seal member is prevented from moving to the opening side. As a result, the occurrence of a gap between the layer thickness regulating portion and the seal member can be suppressed, so that toner leakage can be further suppressed.

  According to the fourth aspect of the present invention, the groove portion is formed so that the length of the bottom portion on the thin plate member side in the rotation axis direction is gradually shortened toward the downstream side in the rotation direction of the developing roller. The member comes into closer contact with both side walls of the groove as it goes downstream in the rotation direction of the developing roller. That is, the groove portion suppresses the seal member from moving in the rotation direction of the developing roller when the developing roller is rotating. As a result, the occurrence of a gap between the layer thickness regulating portion and the seal member can be suppressed, so that toner leakage can be further suppressed.

  According to the fifth aspect of the present invention, the seal member extends from the portion where the seal member is assembled in the groove portion to the upstream side in the rotation direction of the developing roller and extends in the rotation axis direction of the developing roller, and the layer thickness regulating portion. Since the extending portion is engaged, the extending portion engages with the layer thickness regulating portion when the developing roller rotates, so that the seal member moves in the rotating direction of the developing roller. Suppress. As a result, the occurrence of a gap between the layer thickness regulating portion and the seal member can be suppressed, so that toner leakage can be further suppressed.

  According to the invention of claim 6, the seal member has the raised material, and as the raised material goes to the downstream side in the rotation direction of the developing roller, the seal member is tilted toward the oblique direction toward the inner side in the rotation axis direction. Therefore, when the toner enters the surface of the seal member, the toner moves along the direction in which the raised material is tilted. That is, the toner moves back to the opening. Thereby, toner leakage can be further suppressed.

  According to invention of Claim 7, since the sealing member is comprised so that the outer side edge part of the base material in a rotation axis direction may protrude outside rather than the outer side edge part of the raising material in a rotation axis direction. The raised material is not elastically deformed more than the base material when the sealing member is fitted in the groove. Therefore, when the seal member is fitted, it is possible to prevent the raised material from rising and the raising direction of the raised material from becoming uneven. As a result, toner leakage can be further suppressed.

  According to the eighth aspect of the present invention, since the process unit includes the developing device according to any one of the first to seventh aspects, the same effects as those described with respect to the first to seventh aspects are provided. There is an effect.

  According to the invention described in claim 9, since the image forming apparatus includes the process unit described in claim 8, the same effect as described in relation to claims 1 to 8 is obtained. be able to.

Side sectional view showing schematic configuration of color laser printer 1 is a perspective view of the developing cartridge in FIG. Central sectional view of the developing cartridge in FIG. Schematic diagram of the blade unit in FIG. (A) Explanatory drawing before assembling the blade seal member when the right end portion of the developing cartridge in FIG. 2 is viewed from below, (b) Blade seal when the right end portion of the developing cartridge in FIG. 2 is viewed from below Explanatory drawing after assembling members Explanatory drawing when the right end part of the leaf | plate spring member of Fig.5 (a) is seen from the front side in order to demonstrate the assembly | attachment of a blade seal member. Explanatory drawing for demonstrating the groove part of a modification Explanatory drawing for demonstrating the groove part of a modification Explanatory drawing for demonstrating the groove part of a modification Explanatory drawing for demonstrating the braid | blade seal member of a modification. Explanatory drawing for demonstrating the braid | blade seal member of a modification.

Embodiment 1
<Overall configuration of color laser printer>
FIG. 1 is a side sectional view showing a schematic configuration of a color laser printer 1 as an example of an image forming apparatus according to the first embodiment.

  As shown in FIG. 1, the color laser printer 1 includes a main body housing 2, and in the main body housing 2, a paper feeding unit 3 that supplies paper to the image forming unit 4, and an image on the fed paper. Are further provided with an image forming unit 4 for forming the paper and a paper discharge unit 5 for discharging the paper on which the image is formed.

  In the following description, unless otherwise specified, the vertical direction shown in FIG. 1 is up and down, the right side in FIG. 1 is front, the left side is rear, the back side of the paper is right, and the front side of the paper is left. Indicates. The direction here is defined based on the direction seen from the person standing in front of the color laser printer 1.

The main body housing 2 is provided with a cover 21 that can be opened and closed.
The cover 21 is rotatably supported by a cover shaft (not shown) provided at the lower end thereof. When the cover 21 is closed (closed state), the opening is closed by the cover 21. When the cover 21 is opened (open state), the opening is opened. The user can attach and detach the unit main body 61 in which the developing cartridges 7 of the respective colors as an example of the developing device described later are mounted from the opening.

(1) Paper Feed Unit The paper feed unit 3 includes a paper feed tray 31 that stores paper, a paper feed roller 32, and a registration roller 33 below the main body housing 2.
In the sheet feeding unit 3 configured as described above, the sheets are separated one by one from the sheet feeding tray 31 and sent to the image forming unit 4.

(2) Image Forming Unit The image forming unit 4 includes an exposure unit 41, a process unit 6, a transfer unit 8, and a fixing unit 9.

(2-1) Exposure Unit The exposure unit 41 is provided in the upper part of the main body housing 2 and includes a laser light emitting unit, a polygon mirror, a lens, and a reflecting mirror (not shown).

  In the exposure unit 41 configured in this way, laser light emitted from a laser light source based on predetermined image data is scanned at high speed in the left-right direction by a polygon mirror, and passes or reflects through a lens and a reflecting mirror. The photosensitive drum 62 is irradiated.

(2-2) Process Unit The process unit 6 is disposed below the exposure unit 41 and above the paper feed unit 3. The process unit 6 includes a unit main body 61 and a developing cartridge 7 containing toner of each color mounted on the unit main body 61.

  The unit main body 61 is arranged side by side from the front side to the rear side, and has four drum subunits corresponding to the developing cartridges 7 of the respective colors.

  Each drum subunit includes a photosensitive drum 62 and a scorotron charger 63.

  The developing cartridge 7 includes a developing casing 70, a developing roller 71 rotatably supported by the developing casing 70, a supply roller 72 that supplies toner to the developing roller 71, and a toner that contains toner as an example of a developer. And an accommodating portion 78.

  The developing cartridge 7 contains toner for each color of black, yellow, magenta, and cyan, and is arranged in this order from the upstream side of the sheet conveyance direction. Each developing cartridge 7 has the same configuration except that the color of the toner stored in the toner storage section 78 is different.

  The developing roller 71 has a metal roller shaft and a covering portion that covers the roller shaft with a conductive rubber material. In the covering portion, a surface made of conductive urethane rubber or silicone rubber containing carbon fine particles or the like is coated with a coating layer of urethane rubber or silicone rubber containing fluorine. The covering portion is a portion that comes into contact with the photosensitive drum 62.

  The supply roller 72 has a metallic roller shaft and a covering portion that covers the roller shaft with a conductive foam material.

  For example, non-magnetic one-component polymerized toner is used as a developer in the toner storage portion 78. The polymerized toner has a substantially spherical shape and good fluidity. The toner container 78 is provided with an agitator 79 for stirring the toner in the toner container 78.

  In the process unit 6 configured as described above, the surface of the photosensitive drum 62 is uniformly charged by the charger 63, and the charged surface of the photosensitive drum 62 is exposed by scanning with laser light. As a result, the electrostatic latent image is formed on the surface of the photosensitive drum 62.

  On the other hand, the toner in the toner container 78 is supplied onto the developing roller 71 by the supply roller 72 and is frictionally charged between the supply roller 72 and the developing roller 71.

  The toner supplied from the developing cartridge 7 is held on the exposed portion of the photosensitive drum 62, so that a toner image is formed on the surface of the photosensitive drum 62.

(2-3) Transfer Unit The transfer unit 8 is disposed above the paper feed unit 3 and below the process unit 6. The transfer unit 8 includes a driving roller 81, a driven roller 82, a sheet of paper to the fixing unit 9, and a conveyance belt 83 and a transfer roller 84 on which a test image to be described later is formed.

  The driving roller 81 and the driven roller 82 are spaced apart and arranged in parallel, and an endless conveyance belt 83 is stretched between them. The outer surface of the conveyor belt 83 is in contact with each photosensitive drum 62. In addition, four transfer rollers 84 that sandwich the conveyance belt 83 between the photosensitive drums 62 are disposed inside the conveyance belt 83. A transfer bias is applied to the transfer roller 84 in order to transfer the toner image on each photoconductive drum 62 onto a sheet.

  In the transfer unit 8 configured as described above, the sheet transported by the transport belt 83 during image formation is transported between the photosensitive drum 62 and the transfer roller 84 disposed inside the transport belt 83. Then, the toner image held on the photosensitive drum 62 is transferred to a sheet.

(2-4) Fixing Unit The fixing unit 9 is provided on the rear side with respect to the developing cartridge 7 and includes a heating roller 91 that is heated by a heat source and a pressure roller 92 that is in pressure contact with the heating roller 91.

  In the fixing unit 9 configured as described above, the toner image on the paper is heat-fixed on the paper as the paper passes between the heating roller 91 and the pressure roller 92.

(3) Paper Discharge Unit The paper discharge unit 5 includes a paper discharge roller 51 for conveying the paper that has passed through the fixing unit 9, and a paper discharge tray 52 that accumulates the paper conveyed by the paper discharge roller 51. Yes.

  In the paper discharge unit 5 configured as described above, the paper on which the toner image is fixed by the fixing unit 9 is conveyed by the paper discharge roller 51 and discharged onto the paper discharge tray 52.

<Specific configuration of developing cartridge>
Next, the detailed configuration of the developing cartridge 7 which is a characteristic part of the present invention will be described with reference to FIGS.

  Hereinafter, the developing cartridge 7 will be described with reference to the state when the main body housing 2 is mounted. The configuration of the four developing cartridges 7 is the same except that the color of the toner to be stored is different.

  As shown in FIG. 2, the developing cartridge 7 includes a developing casing 70 as an example of a housing, the developing roller 71 (the developing roller 71 is omitted in FIG. 2), and a supply roller 72. A blade unit 73, an elastically deformable side seal member 74 slidably in contact with both ends of the developing roller 71, a blade seal member 75 as an example of a seal member, and a lower film 76 slidably in contact with the lower side of the developing roller 71, It has further. The developing roller 71 rotates in the direction X of the arrow shown in the drawing, and rotates so as to be in sliding contact with the lower film 76, the side seal member 74, and the blade seal member 75 in this order.

<Configuration of developing casing>
The developing casing 70 includes a bearing portion 70a that rotatably supports the developing roller 71, an opening portion 70b for supplying the toner in the toner storage portion 78 to the developing roller 71 via the supply roller 72, and an opening in the left-right direction. The side seal attaching surface (not shown) provided outside the both end portions of the portion 70b, to which the side seal member 74 is attached, and the lower film attaching surface (not shown) to which the lower film 76 is attached. ) And is mainly formed.

  The opening 70b is formed in a substantially rectangular shape that is long in the left-right direction (the direction of the rotation axis of the developing roller 71), and a blade unit 73 described later is fixed to the developing casing 70 above the opening 70b. .

<Configuration of blade unit>
As shown in FIG. 4, the blade unit 73 includes a layer thickness regulating blade 77 as an example of a layer thickness regulating member that regulates the thickness of the toner layer carried on the outer peripheral surface of the developing roller 71, and a metal plate-like member. The member is formed by bending the member substantially at a right angle, and includes a blade holder 73a for holding the layer thickness regulating blade 77 and a blade reinforcing plate 73b.

  The blade holder 73a and the blade reinforcing plate 73b are configured by mounting portions 73c and 73d extending in the vertical direction and sandwiching portions 73e and 73f extending in the left-right direction and sandwiching the layer thickness regulating blade 77.

  As shown in FIG. 4, fixing holes (not shown) for fixing the blade unit 73 to the developing casing 70 with fixing screws 73g are formed at both ends of the mounting portions 73c and 73d in the left-right direction. Further, an adjustment hole (not shown) for holding the layer thickness regulating blade 77 between the blade units 73 by an adjusting screw 73h for adjusting the force for clamping the layer thickness regulating blade 77 is formed in the central portion of the attachment portions 73c and 73d. Has been.

  Boss (not shown) for positioning the layer thickness regulating blade 77 on the blade holder 73a is formed at both ends of the clamping portion 73e of the blade holder 73a in the left-right direction.

  As shown in FIGS. 4 and 5, the layer thickness regulating blade 77 is a plate spring member 77a formed in a thin plate shape that is long in the left-right direction, and a layer thickness regulation fixed to the lower end portion (tip portion) of the leaf spring member 77a. A pressing portion 77b as an example of the portion and an engaging portion 77c as an example of a fixing member provided outside the outer wall portion 77e of the pressing portion 77b in the left-right direction are configured.

  The leaf spring member 77a has a substantially rectangular shape and is made of a thin metal plate such as stainless steel. Engagement holes 77i that engage with bosses formed in the sandwiching portions 73e of the blade holder 73a are formed at both ends of the leaf spring member 77a in the left-right direction.

  The pressing portion 77b is made of elastic rubber such as silicone rubber, and is fixed on the leaf spring member 77a. The length of the pressing portion 77b in the left-right direction is formed to be longer than the region D of the developing roller 71 corresponding to the maximum width of the paper used in the laser printer 1.

  As shown in FIG. 3, the pressing portion 77b is in pressure contact with the outer peripheral surface of the developing roller 71 by the elastic force of the leaf spring member 77a. The pressing portion 77 b regulates the thickness of the toner layer on the developing roller 71 by contacting the developing roller 71 via the toner layer on the developing roller 71.

  The engaging portion 77c is made of an elastic rubber such as silicone rubber like the pressing portion 77b. When the developing roller 71 is assembled to the bearing portion 70a of the developing casing 70 as shown in FIG. It is fixed on the leaf spring member 77 a so as not to come into contact with both ends of 71.

  Further, the engaging portion 77c is disposed with a space L between the engaging portion 77c and the pressing portion 77b in the left-right direction. Furthermore, the engaging portion 77c is disposed so as to be outside the side seal member 75 described later in the left-right direction when the blade unit 73 is assembled to the developing casing 70. That is, as shown in FIGS. 5A and 6, the engaging portion 77 c is a leaf spring located outside the side seal attaching surface provided outside the both ends of the opening 70 b in the left-right direction. By being fixed on the member 77a, a groove portion 77d having a length L in the left-right direction is formed at both ends of the leaf spring member 77a by the pressing portion 77b and the contact portion 77c.

More specifically, the groove 77d is a space in which the outer wall 77e of the pressing portion 77b in the left-right direction and the inner wall 77f of the engaging portion 77c in the left-right direction are substantially parallel. For example, in this embodiment, the distance L is 4.85 mm and the depth (length in the vertical direction) h is 1.5 mm. In other words, the pressing portion 77b and the engaging portion 77c are formed to have the same height.
The engaging portion 77c configured in this manner has a hardness of 80 degrees as measured by a durometer (Polymer Equipment Co., Ltd. CL-150).

  Further, the pressing portion 77b and the engaging portion 77c are formed by injection molding. More specifically, the plate spring member 77a is inserted into the mold, and the elastic material of the pressing portion 77b and the engaging portion 77c is poured therein, whereby the pressing portion 77b and the engaging portion are placed on the plate spring member 77a. 77c is formed.

<Side seal member>
As shown in FIG. 2, the side seal member 74 is a seal member that suppresses the toner from leaking outside the both ends of the opening 70 b in the left-right direction. The side seal member 74 is configured by bonding a base material having elasticity and a surface member laminated on the surface of the base material on the developing roller 71 side with a double-sided tape or the like. The side seal member 74 is disposed between both end portions 71a of the developing roller 71 and the side seal attachment surface, and is fixed to the side seal attachment surface with a double-sided tape, an adhesive, or the like.

  The base material is formed of an elastic body such as urethane sponge which is softer than the surface member and can be elastically deformed. The surface member is made of a material such as felt thinner than the base material, and is fixed to the base material with a double-sided tape or the like.

<Configuration of lower film member>
The lower film 76 is a seal member that slidably contacts the surface of the developing roller 71 along the left-right direction and suppresses toner from leaking between the surface of the developing roller 71 and the developing casing 70. The lower film 76 is a member on a sheet made of a flexible material such as a PET (polyethylene terephthalate) sheet or a rubber sheet.

  The lower film 76 is fixed to the lower film attaching surface of the developing casing 70 with a double-sided tape or the like. Further, the lower film 76 is configured such that both ends of the lower film 76 protrude from the support portion and overlap the side seal member 74 in a state where the lower film 76 is fixed to the lower film attaching surface.

<Configuration of blade seal member>
Since the blade seal member 75 is in close contact with the outer wall 77e of the layer thickness regulating portion, the toner leaks out of the housing through the space between the outer wall 77e and the inner wall 75a of the blade seal member 75. It is a member for suppressing.

  As shown in FIGS. 5B and 6, the blade seal member 75 has a substantially rectangular shape when viewed from the front, and is located outside the region D of the developing roller 71 in the left-right direction, that is, from both ends of the opening 70b. Is also arranged outside. Further, the blade seal member 75 is disposed such that the upstream end portion of the blade seal member 75 in the rotation direction X of the developing roller 71 is in contact with the side seal member 74.

  Further, the blade seal member 75 is configured such that the length A in the left-right direction of the blade seal member 75 is longer than the interval L between the groove portions 77d. More specifically, the blade seal member 75 is formed so that the length A in the left-right direction is 5.5 mm and the depth (length in the vertical direction) H is 1.3 mm.

  The blade seal member 75 includes a base material 752 having elasticity and a raised portion 751 as an example of a raised material provided on the surface of the base material on the developing roller 71 side.

The base material 752 is formed of an elastic body that can be elastically deformed, such as urethane sponge.
The raised portions 751 are configured to be raised by weaving thin Teflon (registered trademark) fibers in a base fabric portion in which, for example, polyester warp yarns and cotton weft yarns are knitted. The raised portion 751 is attached to the base material 752 with a double-sided tape. Further, as shown in FIG. 5, the raised portions 751 are configured in a state where a plurality of raised portions are tilted in an oblique direction toward the center side of the opening portion 70 b as it goes downstream in the rotation direction of the developing roller 71. ing. Further, the raised portions 751 and the base material 752 are formed to have the same length in the left-right direction. More specifically, the height of the base material is 0.4 mm, the height of the double-sided tape is 0.15 mm, and the height of the raised material is 0.75 mm.

  Further, when the developing roller 71 is assembled to the developing casing 70, the blade seal member 75, the pressing portion 77b, and the engaging portion 77c are elastically deformed so as to have substantially the same height in the left-right direction.

  When the blade seal member 75 configured in this way is measured by a durometer (CL-150, Polymer Instruments Co., Ltd.), it has a hardness of 75 degrees. That is, the hardness of the blade seal member 75 is set so as to be softer than the engaging portion 77c.

  Further, when the developing roller 71 is assembled to the developing casing 70, the blade seal member 75, the pressing portion 77b, and the engaging portion 77c are elastically deformed so as to have substantially the same height in the left-right direction.

<Action and effect>
The operation and effect of the laser printer configured as described above will be described.
On both ends of the leaf spring member 77a, a groove portion 77d having a spacing L in the left-right direction is formed by the pressing portion 77b and the engaging portion 77c. When the blade seal member 75 longer than the interval L is fitted into the groove 77d, both wall portions of the groove portion 77d (the outer wall portion 77e of the pressing portion 77b and the inner wall portion 77f of the engaging portion 77c) are replaced with the blade seal member. The two wall portions 75 (the inner wall portion 75a and the outer wall portion 75b of the blade seal member 75) are pressed.

That is, by fitting the blade seal member 75 into the groove portion 77d, the outer wall portion 75a of the blade seal member 75 and the outer wall portion 77e of the pressing portion 77b are brought into close contact with each other. Therefore, the blade seal member 75 prevents the toner from leaking outside the developing casing through the space between the outer wall portion 75a of the blade seal member 75 and the outer wall portion 77e of the pressing portion 77b.
As a result, the blade seal member 75 simply fits into the groove 77d, and the outer wall portion 75a of the blade seal member 75 and the outer wall portion 77e of the pressing portion 77b are in close contact with each other. There is no need to attach the blade seal member 75 to the leaf spring member 77a.

  Further, the raised portions of the blade seal member 75 are configured in a state where a plurality of raised portions are tilted in an oblique direction toward the center side of the opening portion 70b as it goes downstream in the rotation direction of the developing roller 71. Therefore, even if the toner enters the surface of the blade seal member 75, the toner moves back to the opening 70b in the direction in which the raised material is tilted. As a result, toner leakage from the opening 70b can be further suppressed.

<Modification>
The bottom of the groove 77d on the leaf spring member 75 side is a flat surface, but a saw blade shape may be formed on the surface as shown in FIG. More specifically, the groove portion 77d has a saw blade shape in which the tip of the blade is inclined inward in the left-right direction on the bottom surface of the groove portion 77d facing the lower surface of the blade seal member 75 when the blade seal member 75 is assembled to the groove portion. Is formed.

When the blade seal member 75 is fitted into the groove 77d, the bottom surface of the blade seal member 75 and the tip of the saw blade first come into contact with each other.
Further, when the blade seal member 75 is pressed, the blade tip falls while the blade seal member 75 is moved inward in the left-right direction. That is, when the blade seal member 75 is assembled to the groove portion 77d, the outer wall portion 77e of the pressing portion 77b and the inner wall portion 75a of the blade seal member 75 are more closely attached.
When the developing roller 71 is assembled to the bearing portion 70a of the developing casing 70, the blade seal member 75 is always in contact with both end portions of the developing roller 71 as shown in FIG. It will be in the state pressed to the outer side wall part 77e side of the press part 77b.

  With such a configuration, when the blade seal member 75 is fitted into the groove 77d, the blade seal member 75 is assembled to the groove 77d so that the blade seal member 75 moves to the outer wall 77e side of the pressing portion 77b. Therefore, since the blade seal member 75 is more closely attached to the outer wall 77e of the pressing portion 77b, toner leakage can be further suppressed.

  The groove 77d is a space in which the outer wall 77e of the pressing part 77b and the inner wall 77f of the engaging part 77c are substantially parallel to each other, but as shown in FIG. 8, the opening facing the developing roller 71 of the groove 77d. The length C of the portion may be formed to be shorter than the length L of the bottom portion on the leaf spring member 77a side. More specifically, the length C of the contact surface side of the groove 77d that contacts the developing roller 71 is 3.85 mm.

  With this configuration, the blade seal member 75 is restricted from moving toward the contact surface (opening portion) of the developing roller 71 after the blade seal member 75 is assembled in the groove 77d. As a result, the occurrence of a gap between the pressing portion 77b and the blade seal member 75 can be suppressed, so that toner leakage can be further suppressed.

  The groove 77d is a space in which the outer wall 77e of the pressing part 77b and the inner wall 77f of the engaging part 77c are substantially parallel, but as shown in FIG. 9, both side walls 77e, 77f of the groove 77d. May be configured to become narrower toward the downstream side in the rotation direction X of the developing roller 71.

  With such a configuration, the groove 77d suppresses the blade seal member 75 from moving in the rotation direction X of the developing roller 71 when the developing roller 71 is rotating. As a result, the occurrence of a gap between the pressing portion 77b and the blade seal member 75 can be suppressed, so that toner leakage can be further suppressed.

  In the case of the groove portion having such a configuration, the shape of the blade seal member 75 may be the same as that of the groove portion. Even in this case, the length of the blade seal member in the left-right direction is longer than the distance between the side walls 77e, 77f of the groove 77d.

  Further, as shown in FIG. 5A, in the groove portion 77d, the outer wall 77e of the pressing portion 77b and the inner wall 77f of the engaging portion 77c are substantially parallel in the rotation direction X of the developing roller. However, the groove 77d in the rotation direction X of the developing roller may be connected. More specifically, the outer wall 77e of the pressing portion 77b in the rotation direction X of the developing roller and the inner wall 77f of the engaging portion 77c in the rotation direction X of the developing roller may be connected.

  With such a configuration, it is possible to easily flow the elastic material when forming the pressing portion 77b and the engaging portion 77c.

  The blade seal member 75 has a substantially rectangular shape. However, as shown in FIG. 10, the blade seal member 75 has a substantially L shape when viewed from the front. When the blade seal member 75 is incorporated into the groove 77d, the groove portion An extended portion 75c that extends from 77d to the upstream side in the rotation direction X of the developing roller 71 and engages with the pressing portion 77b may be formed. At this time, the length B in the left-right direction of the extending part 75c is formed to be longer than the distance L in the left-right direction of the groove part 77d. More specifically, the extension part 75c is formed so that the length B in the left-right direction is 7.0 mm.

  With such a configuration, even when the developing roller 71 rotates and the blade seal member 75 moves downstream in the rotation direction X, the extension portion 75c is engaged with the pressing portion 77b. The blade seal member 75 can be restricted from moving in the rotation direction X of the developing roller 71. As a result, the occurrence of a gap between the pressing portion 77b and the blade seal member 75 can be suppressed, so that toner leakage can be further suppressed.

  The blade seal member 75 is formed so that the raised portions 751 and the base material 752 have the same length in the left-right direction. However, as shown in FIG. 11, the outer end 752b of the base material 752 in the left-right direction. However, you may form so that it may protrude outside the outer side edge part 751b of the raising part 751 in the left-right direction.

  With such a configuration, the raised portion 751 is not more elastically deformed than the base material 752 when the blade seal member 75 is fitted into the groove portion 77d. Therefore, when the blade seal member 75 is fitted, the raised portions 751 are lifted, so that the raising direction of the raised portions 751 can be prevented from becoming uneven. As a result, toner leakage can be further suppressed.

DESCRIPTION OF SYMBOLS 1 ... Color laser printer, 2 ... Main body housing, 4 ... Image formation part, 6 ... Process part, 62 ... Photosensitive drum, 7 ... Developing cartridge, 70 ... Development casing, 70a ... bearing, 70b ... opening, 71 ... development roller, 73 ... blade unit, 73a ... blade holder, 73b ... blade reinforcement plate, 73c, 73d ..Mounting part, 73e, 73f ... clamping part, 74 ... side seal member, 75 ... blade seal member, 75a ... inner wall part, 76 ... lower film, 77 ... layer Thickness regulating blade, 77a ... leaf spring member, 77b ... pressing part, 77c ... engaging part, 77d ... groove part, 77e ... outer wall part, 77f ... inner wall part

Claims (9)

A developing roller carrying a developer on the outer peripheral surface;
A housing that rotatably supports the developing roller and has an opening extending in a rotation axis direction of the developing roller;
A thin plate member having one end fixed to the housing and extending along the rotational axis direction of the opening, and a free end portion of the thin plate member fixed to the outer periphery of the developing roller via a developer A layer thickness regulating member that regulates the thickness of the developer layer on the outer circumferential surface of the developing roller;
A fixing member which is fixed on the thin plate member outside the both end portions of the layer thickness regulating portion in the rotation axis direction and forms a groove portion with the layer thickness regulating portion;
A seal member that has a length longer than the length of the groove portion in the rotation axis direction, and suppresses leakage of the developer outside the housing by being fitted into the groove portion;
A developing device comprising: In the groove,
2. A saw blade shape in which a tip is inclined inward in the rotation axis direction is formed on a bottom surface of the groove portion facing the lower surface of the seal member when the seal member is assembled to the groove portion. The developing device according to 1. The groove is
3. The developing device according to claim 1, wherein the length of the opening facing the developing roller in the rotation axis direction is shorter than the length of the bottom on the thin plate member side. . The groove is
The length of the bottom portion on the thin plate member side in the rotation axis direction is formed so as to be gradually shortened toward the downstream side in the rotation direction of the developing roller. The developing device according to any one of the above. The sealing member is
The seal member has an extension portion extending from the portion assembled in the groove portion to the upstream side in the rotation direction of the developing roller and extending in the rotation axis direction of the developing roller to engage with the layer thickness regulating portion. The developing device according to any one of claims 1 to 4. The sealing member is
A substrate having elasticity;
A brushed material provided on the substrate,
The raised material is
6. The developing device according to claim 1, wherein the developing device is tilted in an oblique direction toward an inner side of the rotation axis direction toward a downstream side in a rotation direction of the developing roller. . The sealing member is
The image according to claim 6, wherein an outer end portion of the substrate in the rotation axis direction is configured to protrude outward from an outer end portion of the raised material in the rotation axis direction. Forming equipment. A developing device according to any one of claims 1 to 7,
And a photoconductor on which a developer image is formed by supplying the developer from the developing device. An image forming apparatus comprising the process unit according to claim 8,
Exposure means for scanning the photoconductor with light;
Transfer means for transferring the developer image formed by the process unit to paper;
Fixing means for fixing the developer image formed on the paper;
An image forming apparatus comprising: